KR100372607B1 - a - Google Patents

Abstract

The present invention relates to an onboard PCM encoder, which is a device that collects various data acquired during flight mounted on a scientific rocket and a space projectile and configures a data format in an appropriate form. Since the sensors may be installed together, the sampling rate of each sensor is adjusted to suit the characteristics of these sensors, and the present invention relates to a PCM encoder having various sampling rates for transmitting the data to the ground.

The PCM encoder of the present invention includes a controller for creating a format of data, a multiplex for selecting each sensor signal, an A / D converter for converting an analog signal into a digital signal, and a serial bit stream ( It has a serial converter which converts to Serial Bit Stream, a code converter which converts NRZ (None Return Zero) code into BIΦ code, and a controller which provides control signal to channel selection and A / D converter.

Description

Rocket mounted PCM encoder with various sampling rates {a}

The present invention relates to a mounted PCM (Pulse Code Modulation) encoder, which is a device configured to collect various data acquired during flight mounted on a scientific rocket and a space projectile and configure a data format in an appropriate form. It is necessary to mount a large number of sensors and a small number of sensors on the projectile, so that the sampling rate of each sensor is adjusted to suit the characteristics of these sensors. It is about.

Scientific rockets and space launch vehicles include sensors for scientific observation (ozone sensors, ion mass spectrometers, high-rise atmospheric spectroscopy, electronic measuring instruments, etc.), and sensors for measuring flight performance (temperature, pressure, vibration, shock, acceleration, displacement, stress). Etc.), sensors for measuring the performance of the propulsion engine (pressure, vibration, propellant level, etc.) and sensors for measuring the performance of the attitude control system (pressure, command input of each stage, etc.) During flight, various data generated during the flight are acquired and transmitted to the ground in real time.

However, the sensors mounted on the projectile require various sampling rates according to the characteristics of the signal.

For example, the sampling rate of a basic PCM encoder is designed to be 200 samples / sec in consideration of the characteristics of the mounted sensor and the transmission speed of telemetry, but the sensor for shock measurement, the sensor for vibration measurement, and the propulsion engine Like the sensor measuring pressure change, the signal change per unit time requires a high sampling rate (1K ~ 10K Sample / Sec), and the signal change per unit time such as power sensor used in pressure sensor, temperature sensor, stress sensor, and mounting part Less requires a low sampling rate (10 to 20 Sample / Sec).

In addition, the PCM encoder for mounting should have the characteristics that the system is simple and flexible enough to cope with the sampling rate required by various sensors. However, in general, the data acquisition device described above can realize a signal of a sensor requiring a high sampling rate based on a basic sampling rate by combining a plurality of available channels.

However, since a plurality of channels are tied to one sensor output, there is a problem in that the maximum sampling rate is limited by the ability of the sensor output to drive a load.

Technology related to rockets and space launch vehicles was not disclosed by the Missile Technology Control Regime (MTCR) of developed countries.However, the technology currently used uses one sensor output for channels requiring high sampling rates. It is estimated that a channel that acquires data using a plurality of channels and requires a low sampling rate acquires data by forming a hierarchical structure using a plurality of multiplexes. In case of a sensor requiring a circuit, a circuit must be configured to drive several channels at the same time. In the case of a sensor requiring a low sampling rate, multiple layers of multiplexes must be used, which makes the hardware and controller fabricated complicated. .

The present invention is intended to construct a PCM encoder for mounting a simple circuit while maintaining the sampling rate required by each sensor when the flight performance data and observation data are mounted on a vehicle and transmitted to the ground.

In other words, the purpose of the system is to configure the onboard system that simplifies the configuration of the onboard system to minimize the causes of failures during flight while maximizing the data acquisition capability and the use efficiency of the telemetry channel.

Therefore, the present invention assigns a unique address for each channel, configures the circuit so that all sensors and analog multiplexes have a one-to-one correspondence, and then increases the frequency of connection for a channel requiring a high sampling rate. The user can adjust the rate arbitrarily and use it to reduce the frequency of connection to the channel that requires low sampling rate, so that the appropriate sampling rate can be maintained to acquire a large number of sensor data in one channel of telemetry. An onboard PCM encoder can be achieved that uses the channel efficiently while maintaining a sampling rate appropriate for the characteristics of the sensor used.

1 is a configuration diagram of an embodiment of the present invention Figure 2 is a timing chart of the main signal according to an embodiment of the present invention

[Explanation of symbols on the main parts of the drawings]

S1 to Sn: mounted sensor U1: analog multiplex

U2: A / D Converter U3: Serial to Parallel Converter

U4: Code Converter U5: Low Pass Filter

U6: controller

(D0: Dn): A / D converted parallel data consisting of n bits

(A0: An): Channel selection signal of analog multiplex

The present invention relates to a mounted PCM (Pulse Code Modulation) encoder, which is a device configured to collect various data acquired during flight mounted on a scientific rocket and a space projectile and configure a data format in an appropriate form. It is necessary to mount a large number of sensors and a small number of sensors on the projectile, so that the sampling rate of each sensor is adjusted to suit the characteristics of these sensors. The present invention relates to an analog multiplex U1 for selecting a sensor S1-Sn signal mounted on a projectile as a selection signal A0: An of a controller U6,

An A / D converter U2 for converting the signal selected in the analog multiplex U1 into digital data D0: Dn by the control signal of the controller U6,

Serial-to-parallel converter (U3) for converting the data (D0: Dn) converted in the A / D converter (U2) into serial data by the control signal of the controller (U6),

A code converter U4 for converting the NRZ-L code converted by the serial-parallel converter U3 into a BIΦ-L code by a control signal of the controller U6,

And a controller U6 which provides the channel selection and A / D conversion and serial and parallel conversion and code conversion control signals described above.

The present invention acquires data suitable for the sampling rates required by the sensors (S1-Sn) mounted on the projectile and requires various sampling rates, and configures the data in an appropriate form and transmits it to the ground.

Here, the controller U6 manages the sampling rate of the entire signal and generates a control signal for starting the A / D conversion for the selected signal after ensuring sufficient time for the signal to faithfully follow the original signal.

In addition, the channel selection signal A0: An of the analog multiplex U1 is generated to match the determined configuration, and the sensor S1 -Sn signal is applied to the input of the A / D converter U2.

Therefore, the signal lines may be connected so that the outputs of the sensors S1-Sn and the inputs of the analog multiplex U1 correspond one-to-one.

The controller U6 adjusts the sampling rate to suit the data change characteristic of the sensor connected to each channel by outputting the channel selection signals of the analog multiplex U1 in any order. In other words, the input of the analog multiplex U1 is controlled. When several types of sensors (temperature, vibration, acceleration, etc.) are connected to the same analog multiplex (10 samples / sec, acceleration 200 samples / sec, vibration 2000 samples / sec), depending on the output characteristics of each sensor. By adjusting the channel selection signal in U1), various kinds of sampling rates can be realized.Introducing such a data processing technique maximizes the number of sensors that can be processed while using the same size data format. In order to compare various types of data samples, information including Sub Frame Identification Code (SFID) and Major Frame Information (FC) is transmitted as shown in FIG. Therefore, in order to extract specific sensor information from the data received from the ground, SFID and FC information can be combined without complex processing to restore accurate sensor data only by position information of a specific sensor in the format. As shown in Figure 2, M2 / M4 acquires data 2/4 times faster than general samples (which can be expanded by multiples of 2 depending on the number of minor frames). It is suitable for transmitting change signals by converting data by selecting / 4 times more, and combining SFID and An information in order to restore the corresponding information on the ground. / n, where n is an integer) to reduce the number of selections compared to the other channels, so that a plurality of sensor definitions can be made through one word. Since the signal can be transmitted, it is suitable for transmitting a signal having a small change in signal. This means that it contains different information according to the information of the FC at the same location. As shown in FIG. It configures the data format and adjusts the channel selection signal of the analog multiplex (U1) so that the data can be read from the sensor at the assigned time of each sensor. The sampling rate used is a multiple of the reference sampling rate or a range of fractions. Otherwise, the time interval between each sample cannot be kept constant.

In order to match the bit rate of the transmission signal, a clock and parallel load signal are provided to the parallel-to-parallel converter U3 to latch the completed A / D conversion signal to the converter. After outputting, 1Bit is output according to the input clock to generate continuous serial bit stream data.

The code converter U4 converts the input NRZ-L code into a BIΦ-L code.

Because NRZ-L code can have the same data value continuously due to the characteristics of the code, it is not possible to check where data change occurs during transmission and restoration. Therefore, BIΦ-L has two states per bit. Conversion to code reduces the likelihood of errors during transmission and restoration.

In addition, the low pass filter (U5) because the BIΦ-L code is a square wave has a frequency characteristic of the entire band, it is required that the bandwidth of the transmitter used when transmitting to the ground by RF (Radio Frequency) is very large.

Therefore, it is used to reduce the bandwidth of the transmitted signal by passing the cut off frequency through the low pass filter U5 at about 1.5 times the bit rate.

The PCM encoder having various sampling rates developed through the present invention can be utilized in a rocket and space projectile data transmission system equipped with various sampling rates and a plurality of sensors through a limited transmission channel.

The present invention refers to a PCM encoder mounted on a rocket as an example of its use, and such a system can be used in the telemetry field that requires the use of a plurality of sensors while requiring various sampling rates. It is effectively used in the field.

Claims (1)

A sensor that acquires various data generated during flight, an analog multiplex that corresponds to the sensor 1: 1 and selects a signal of each sensor, and an A / D that converts a signal selected from the analog multiplex into digital data In the rocket-mounted PCM encoder consisting of a converter and a serial-to-parallel converter for converting the digital data converted by the A / D converter into serial data, A rocket-mounted PCM encoder having various sampling rates, characterized by a controller for adjusting a channel selection signal of an analog multiplex so as to read data from a sensor at an assigned time of each sensor.